Triruthenium dodecacarbonyl

Chembox new
Name = Triruthenium dodecacarbonyl
ImageFile = Ru3(CO)12.png ImageSize = 200px
ImageFile1 = Triruthenium-dodecacarbonyl-from-xtal-3D-balls.png IUPACName = "cyclo"-tris(tetracarbonylruthenium)
(3 "Ru"—"Ru")
OtherNames = Ruthenium carbonyl
Section1 = Chembox Identifiers
SMILES =
CASNo = 15243-33-1
Section2 = Chembox Properties
Formula = C₁₂O₁₂Ru₃
MolarMass = 639.33 g/mol
Appearance = orange solid
Density = 2.48 g/cm³
Solubility = insoluble
Solvent = other solvents
SolubleOther = organic solvents
MeltingPt = 224 °C
BoilingPt = sublimes in vacuum
Section3 = Chembox Structure
CrystalStruct =
Dipole = 0 D
Section7 = Chembox Hazards
ExternalMSDS =
MainHazards = CO source
RPhrases = 11-20
SPhrases = none
Section8 = Chembox Related
OtherCpds = Fe₃(CO)₁₂
Os₃(CO)₁₂

Triruthenium dodecarbonyl is the chemical compound with the formula Ru₃(CO)₁₂. This orange-colored metal carbonyl cluster is a precursor to other organo-ruthenium compounds.

tructure and synthesis

The cluster has D_3h symmetry, consisting of an equilateral triangle of Ru atoms, each of which bears two axial and two equatorial CO ligands. [Slebodnick, C.; Zhao, J.; Angel, R.; Hanson, B. E.; Song, Y.; Liu, Z.; Hemley, R. J., "High Pressure Study of Ru₃(CO)₁₂ by X-ray Diffraction, Raman, and Infrared Spectroscopy", Inorg. Chem., 2004, 43, 5245-52. doi|10.1021/ic049617y ] Os₃(CO)₁₂ has the same structure, whereas Fe₃(CO)₁₂ is different, with two bridging CO ligands, resulting in C_2v symmetry.

Ru₃(CO)₁₂ is prepared by treating solutions of ruthenium trichloride with carbon monoxide, usually under high pressure. [Bruce, M. I.; Jensen, C. M.; Jones, N. L. “Dodecacarbonyltriruthenium, Ru₃(CO)₁₂” Inorganic Syntheses, 1989, volume 26, pages 259-61. ISBN 0-471-50485-8.] [M. Faure, C. Saccavini, G. Lavigne “Dodecacarbonyltriruthenium, Ru₃(CO)₁₂” Inorganic Syntheses, 2004 Vol 34, p. 110. ISBN 0-471-64750-0.] The stoichiometry of the reaction is uncertain, one possibility being the following::6 RuCl₃ + 33 CO + 18 CH₃OH → 2 Ru₃(CO)₁₂ + 9 CO(OCH₃)₂ + 18 HCl

Reactions

The chemical properties of Ru₃(CO)₁₂ have been widely studied, and the cluster has been converted to hundreds of derivatives. High pressures of CO convert the cluster to the monomeric pentacarbonyl, which reverts back to the parent cluster upon standing.:Ru₃(CO)₁₂ + 3 CO $overrightarrow\{leftarrow\}$ 3 Ru(CO)₅ K_eq = 3.3 x 10^-7 mol dm^–3 at room temperatureThe instability of Ru(CO)₅ contrasts with the robustness of the corresponding Fe(CO)₅. The condensation of Ru(CO)₅ into Ru₃(CO)₁₂ proceeds via initial, rate-limiting loss of CO to give the unstable, coordinatively unsaturated species Ru(CO)₄. This tetracarbonyl binds Ru(CO)₅, initiating the condensation. [Hastings, W. R.; Roussel, M. R.; Baird, M. C. “Mechanism of the conversion of [Ru(CO)₅] into [Ru₃(CO)₁₂] ” Journal of the Chemical Society, Dalton Transactions, 1990, pages 203-205. DOI: 10.1039/DT9900000203]

Upon warming under a pressure of hydrogen, Ru₃(CO)₁₂ converts to the tetrahedral cluster H₄Ru₄(CO)₁₂. [Bruce, M. I.; Williams, M. L. “Dodecacarbonyl(tetrahydrido)tetraruthenium, Ru₄(μ-H)₄(CO)₁₂” Inorganic Syntheses, 1989, volume 26, pages 262-63. ISBN 0-471-50485-8.] Ru₃(CO)₁₂ undergoes substitution reactions with Lewis bases::Ru₃(CO)₁₂ + n L → Ru₃(CO)_12-nL_n + n CO (n = 1, 2, or 3)where L is a tertiary phosphine or an isonitrile.

Ru-carbido clusters

At high temperatures, Ru₃(CO)₁₂ converts to a series of clusters that contain interstitial carbido ligands. These include Ru₆C(CO)₁₇ and Ru₅C(CO)₁₅. Anionic carbido clusters are also known, including [Ru₅C(CO)₁₄] ^2- and the bioctahedral cluster [Ru₁₀C₂(CO)₂₄] ^2-. [Nicholls, J. N.; Vargas, M. D. “Carbido-Carbonyl Ruthenium Cluster Complexes” Inorganic Syntheses, 1989, volume 26, pages 280-85. ISBN 0-471-50485-8ISBN.]

References